my jaguar was in my 75gallon for a while with 2 oscars, green terror and salvini. At only 3" he wanted nothing else in that tank but himself. The jag would go out of his way to look for fish when he saw them he would chase and bite until he/she lost them. This turned into a repeated thing. I wasn't planning on keeping them in there for long i had a 200gal already cycled and ready. I was just suprised how territorial if you want to call it that (more aggressive then anything) he was to those fish. Salvini had him on the run for a while with the flaring, but as soon as the jag hit back once the salvini went running. "Aslong as you are prepared for the worst then its not that bad." Whether you have another tank ready or a petshop that will take your troublesome fish always have a backup plan.